> Limiting the access of unencrypted passwords to only properly setup 1PW applications would seem to eliminate the possible (probable?) web based attack vector to a 1password.com account.

This doesn't make sense. What's a "properly setup 1PW application"? Presumably that's an instance of 1Password that has been given both the master password and account key for the account. But when you use the web-based portal, you have to give it, yep, the master password and account key.

Anyone who is able to access the passwords using the web portal can already set up a local instance of the 1PW application that syncs with the same account.

Ultimately, asking to "disable browser access" is basically the same thing as asking to "disable the syncing API", which would obviously defeat the entire point of having the family account.

not sure if it would work for your situation, but it's possible to set up different vaults for different groups of people and share them via separate dropbox folders (or even just different share settings on the vault files). i have 5 vaults set up that way.